In such a vane cell machine the rotor is located with its rotational axis having a distance to a middle axis of the stator bore. Pressure chambers are formed between the rotor, the vanes and the circumferential wall of the stator bore, said pressure chambers being closed axially by said end faces. When the rotor rotates, the vanes are moved radially into and out of the rotor and the pressure chambers increase and decrease their volume. When such a vane cell machine is used as pump, during the increasing phase of the pump chambers fluid is sucked into the stator bore and during the decreasing phase of the pump chambers the fluid is pushed out of the machine. When the vane cell machine is used as motor, inputted fluid under pressure tends to increase the volume of the pump chambers thereby causing a rotation of the rotor.
In any case it is necessary to have sealing means acting on the rotor so that there is no leakage out of the housing when the rotor rotates.
In the vane cell machine mentioned above the sealing means are formed by a sealing ring which is positioned radially inside an outer ring serving as wear element. This makes the construction complicated.